Saw-sharpening machine.



T. HUMPAGE.

sAw SHARPENING MAGHINE.

APPLICATION FILED AUG.'25, 1913.

Patented Nov. 3, 1914.

2 SEIIETS-SHEET 1.

THE NORRIS PETERS CO,;FHO1U-L|THU.. WASHINGTON. D, C.

T. HUMPAGE.

SAW SHARPENING MACHINE. APPLICATION FILED AUG. 25, 1913.

Patented NOV. 3, 1914.

2 SHEETS-SHEET 2.

THE NORRIS PETERS 60., FHOTO-LITH- WASHINGTON Ln c4 To all whom, it may concern: I

saw-blade,

THOMAS H Mrace, or BRISTOL, ENGLAND.

SAW-SHARPEN IN Gr MACHINE. 3

Specification of Letters Patent.

Patented Nov 3, 1914.

Application filed August25, 1913. Serial No. 786,612.

Be 1t known that I, THOMAS HUMPAGE, a-

subject of the King of England, residing at- Bristol, in Gloucestershire, in the Kingdom of England, have invented a new and useful Improvement in Saw-Sharpening Mat-- chines, of which the following is a specification. i 1

My invention has for its object to provide a saw-sharpening machine in whichthe on being advanced tooth by toothand subjected to the action of an abrasive wheel, receives lateral rocking motion so that the teeth areground to the arc of a circle or other curve thereby removing 'the'square corners and greatlyincreasing the eificiency of-the saw.

' Further objects are to provideapivoted arm for carrying the abrasive wheel, means for adjustably limiting the descent of same,- and means for actuating the forward feed of the saw by the rocking member of same.

These and other objects are attained by. the combined mechanism hereinafter fully described with reference to the annexed drawings, in which v I Figure l is a front elevation; Fig. 2, a corresponding plan, partly in section; Fig. 3, a side elevation of the machine;Fig. 4

represents the feeding bar whichfeeds the saw blade forward to the abrasive wheel,

a tooth at a time; Fig. 5 represents the rocking cradle in which. the saw blade is held, in cross-section; Fig. 6 represents the end of the connecting rod and the feeding bar in end elevation and l ig. 7 represents the end of the connectingrod and feeding bar in plan. Figs. 4: to 7 scale. A a I In all the figures the same reference characters denote the same parts. The saw blade 1 to be sharpened iscarried in a rocking cradle 2 the length of the blade being arrangedso as to be. trulypar,- allel to the axis of the cradle. -.The vertic-a1 position of the blade with relation. to the axis of the cradle is capable of adjust ment as described later,=so that the axis about which the blade rocks is situated at some predetermined point near the roots of "the teeth.

The saw blade is not rigidly fixed in the side" of the blade distance above the axis.

are'drawn to a larger 1 rocking cradlebut is 'held while each tooth is ground by, means of suitably arranged spring-pressed plungers 3 which press the 1 against adjustable arms 4 in the body of the cradle.v The strength of the 'springpressed plungers 3 is such that whilethe blade is efficiently held during the process of grinding it may be fed forward as described later without any movement of the spring-plungers. The purpose of the ad ustable arms at is to allow of blades of different thickness being ized in the rocking, cradle.

the saw blade is supported by setting screw 5 in the cradle.

The back of an adjustable ,At each end of the cradle other adjustable supportsd are provided to keep the teeth of the sawblade parallel to the axis of the said cradle."

Two fixed stops 7 for locating the sawblade in in the cradle just above the teeth of the saw one on each'side of the center of the adjustable screw 5. A setting gage rod or bar is provided which can be placed between the tops of the teeth of'the saw-blade and the said fixed stops 7 The saw-blade is then raised by the adjusting screw 5. until the ,settinggage rod is slightly grippedbetween the tops of the teeth and the two fixed stops 7. Thesetting gage rod is then withdrawn, leaving the tops of the teeth at the required setting distanceof the tops of the teeth above the axis of the cradle and thereby, as explained later, thearc to which the teeth are ground willbe made smaller or larger.

A feeding bar an end arm of the cradle and projects the feeding bar is: provided with a few teeth of the same pitch as the to be sharpened, Different bars 8 are provided for difi'erentpitches of the saw teeth.

The teeth on the feeding bar 8 are caused at certain times to mesh with the teeth of the saw 1 and push it forward through the cradle, the pressure being so exerted as to always keep the back of the saw incontact with the adjustable setting screw 5. The feeding bar 8 is .returned by means of a spring 9 attached to the bodyiof the cradle a, vertical direction are provided Thicker or thinn er gage rods can be used to alter the 8 is slidingly carried in,

accurately centrali slightly at one end of it. The inner end of 2 and the bar 8 respectively. The cradle 13 given a rocking motion by means of a connecting rod 10 driven by a crank 11. The

end of the connecting rodwhich is attached to the cradle is provided with a beveled lug 12 which comes in contact with the proj ecting oppositely beveled end of the feeding bar 8, pressing it in and thereby causing the saw blade to be moved forward through the space of one tooth.

The distance traversed by the feeding bar on its forward stroke is capable of adjustment in two ways. First the end of the connecting rod which is provided with the lug 12 is capable of slight movement laterally upon the end of the crank pin 13,'the distance between the body of the cradle and the back face of the lug being regulated by a nut 14 on the crank pin. By this means the amount by which the feeding bar projects from the cradle body when it has reached the forward end of its stroke is adjusted, thus determining the forward limit of the stroke. The second adjustment is made by a screw 15 carried in the body of the cradle 2. This screw bears against a pro-.

jection 16 upon the feeding bar when the latter is in its backward position. By this means it is possible to determine the back ward limit of the stroke of the feeding bar.

An abrasive wheel 17 is carried on an arm 18, which is raised and lowered by a cam 19. This arm is provided with a fine adjustment, to compensate for the wear of the abrasive wheel, by a' locking screw 20, which bears upon the rim or outer surface of the rocking cradle 2. This locking screw limits the depth to which the emery wheel can travel toward the axis of the cradle.

A gage setting block is provided which passes between a gap in the cradle and the grinding edge of the abrasive wheel for setting the edge of the abrasive wheel to the exact grinding depth from the 'aXis ofthe cradle. The reason forgiving the saw-blade a rocking motion during the process of sharpening is to insure that all the teeth are of equal height and ground to atrue arc of a circle or other curvature over the tops, thereby greatly increasing the efficiency of the saw. In place of a cylindrical outer surface, of the cradle 2 upon which the locking screw 20 bears, I may shape this surface to various forms and -therebygrind.

the tops of the teeth to any other curved form.

I claim: I V

1. A hack-saw sharpening machine comprising operating mechanism and means for mechanically rocking the saw-blade laterally during the sharpening operation, means in combination with said rocking means for advancing the saw-blade tooth by tooth, a

in the cradle, a feed bar traveling abrasive wheel, and means for limiting the descent of said wheel, as described.

2. In a hack-saw sharpening machine, the combination with a bed, of a rocking cradle, means for securing a saw-blade teeth up ward in said cradle, means for automatically advancing the saw-blade in its cradle, an abrasive wheel, and mechanism for rocking said cradle and for operating the abrasive wheel, as described.

3. In a hack-saw sharpening machine, the combination with a bed, of a lower rocking cradle, means for horizontally adjusting a saw-blade in and parallel to the axis of said cradle, means for advancing the saw-blade in said cradle, an abrasive wheel, and operating mechanism for said parts, as described.

4:. In a hack-saw sharpening machine, the combination with a bed, of a transverse rocking cradle, means for horizontally ad j usting a saw-blade in said cradle, means for centralizing the saw blade and means for advancing the saw-blade in said cradle, an abrasive wheel, a swing arm carrying said wheel, and operating mechanism for said parts, as described. 1

5. In a haclcsaw sharpening machine, the combination with a bed, of a rocking cradle, means for adjustably securing a saw-blade in the cradle, a crank and connecting rod for rocking the latter, means on the cradle for advancing the blade, means on the connecting rod for controlling the advance, an abrasive wheel, and operating mechanism for said parts, as described. 7

6. In a hack-saw sharpening machine, the combination with a bed, of a rocking cradle, means for adjustably securing a saw-blade those of the saw-blade, slidably mounted in said cradle, a connecting rod to rock the same, a beveled lug on the connecting rod scribed.

combination with a bed, of a rocking cradle,

means for adjustably securing a saw-blade slidably mounted in said cradle, a spring for returning'the feed bar, an abrasive wheel, and operating mechanism for said parts, as described.

8. In a hack-sawsharpening machine, the combination with a bed, of a rocking cradle, means for adjustably securing a saw-blade in thecradle, means for rocking the latter, a feed bar slidably mounted in said cradle and meshing with the saw-blade, means for operating and adjusting the forward stroke of said feed bar, means for limiting the rearward stroke of same, an abrasive wheel, and

scribed.

in the cradle, a feed bar, with teeth to mesh to move the feed bar, an abrasive wheel, and operating mechanism for sald parts, as de- 7 In a hack-saw sharpeningmachine, the

9. In a hack-saw sharpening machine, the the cradle for controlling the swing of the combination With a bed, of a rocking cradle, means for adjustably securing a saw-blade in said cradle, a controlled feed bar mounted in the latter, an abrasive Wheel, a pivoted arm carrying said wheel, cooperating means connected with said arm and ith Copies of this patent may be obtained 1 described. a

Witnesses or five cents each, by addressin Washington, D. 0.

arm, and operating means for said parts, as

"THOMAS HUMPAGE.

' E. J. FUSSELL, DANIEL BRITT.

: the Commissioner of Patents. 

